0:15Well welcome to another Lightblade Learning Lab
0:19I hope today it’s going to be quite an interesting day because on the one hand
0:23I’m going to show you something quite interesting on this machine but on the
0:28other hand what I’m gonna tell you is please don’t do it! Now that might sound
0:34dangerous but it’s not to me but maybe just a little bit dangerous to the
0:39Machine and all, all will become evident as we get further into this
0:43little project as I told you before I’m happy to do things on this machine to
0:49demonstrate to you things that you can’t do yourself not entirely true in this
0:55instance you can do it yourself but the warning is that over the long term it
1:02might damage your machine not the tube but the physics of the machine itself so
1:10let’s just push on and you’ll understand my love of this material acrylic it’s
1:16an amazing material now as I’ve demonstrated to you many times before it
1:21is unique amongst materials in that it does not burn what it does it sublimates
1:28it turns directly from a solid to a gas when it heats up we’ve got an invisible
1:34beam of light which is just invisible energy and what happens is when the
1:41energy hits the surface of this material that light energy turns to heat and that
1:47heat immediately causes this stuff to evaporate now today I want to introduce
1:53you to a variant of acrylic and I was recently visiting a local show
2:04room of mine here in Colchester a place called Colchester Worktops
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
2:09now that may well give you a little bit of a clue as to what we’re going to talk
2:13about I went there to visit to get to see if I could get some little bits of
2:19make off cuts of granite that I could use for demonstrating how we can engrave
2:25on granite but that’s not what we’re going to do today while I was there they
2:34had lots of offcuts and samples of this wonderful material now you may well be
2:40familiar with this material already it’s a material called Corian and it’s used
2:47for worktops now it is a mixture of about 30 percent acrylic which is
2:55holding the whole thing together but then it’s been filled with various
2:59colours and types of aluminium oxide well not aluminium oxide it’s aluminium
3:06hydroxide there’s a big difference because aluminium hydroxide is used
3:12normally as a flame retardant, it’s got all sorts of properties that make it basically
3:15chemically inert to be suitable for use as work surfaces now the fact that it
3:25contains 30% acrylic interested me because that raised the
3:32potential for being able to cut it on this machine and maybe engrave it on
3:38this machine the only problem is the aluminum hydroxide that’s in here is a
3:45solid which is not very good at transmitting heat or absorbing infrared
3:52light so I was a little bit hesitant about trying to use it but it had the
4:00possibility of being able to do something with it so what I did was some
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
4:04quick test work to find out if we could cut it and remarkably I’m just about to
4:12show you some footage which shows you some results that I produced earlier on
5:03we have two problems number one
5:08the acrylic melts away nicely surprisingly enough doesn’t burn
5:16what it does
5:23it leaves all this dust behind produces a nice clean edge that’s not burnt
5:41it’s not particularly hot
5:44but look look at all this dust very fine dust and that’s going to be a killer
5:59for these slides which are covered in grease
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
6:04so that’s not going to do the bearings any good at all
6:09so everything is getting covered in a fine dust
6:17we have to run incredibly slowly to cut
7:53so here’s the piece that came out of there
7:57and here’s an acrylic insert cut off the same file
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
8:06for there okay well I did warn for you that that might
8:11be quite interesting there’s a couple of other things I’d like you to just take a
8:14note of number one you saw how bright the cut was tremendous heat in that cut
8:24there was virtually no evaporation taking place that you could see of the
8:30acrylic when you look on the edge of this material it has got the merest
8:34amount of discoloration on it and as you can see here there is a small amount of
8:40discoloration in the bottom of these engraved cuts but it’s remarkably burn
8:47and debris free considering I was blowing on it with a lot of air assist
8:55and under normal circumstances air assist would make it very sticky and
9:00mucky on the surface here so this is a very clean cutting material part of that
9:07property comes from the aluminium hydroxide now the other thing I wanted
9:12you to note was that when I was cutting the temperature on the back here despite
9:17all this white heat that was on there continuously this temperature on the
9:22back was virtually only probably 40 degrees C at the most now why is that no
9:31burns cool cut
9:36well it’s all to do with this aluminium hydroxide as I pointed out to you at the
9:40beginning it’s used as a flame-retardant material and basically what it is the
9:46hydroxide part of it basically means that aluminium has bonded with water
9:50when you heat it up the water actually separates out and that is that water
9:57which is producing the cooling effect so it keeps the cut cool by basically
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
10:04converting the water into a coolant and leaving behind all that horrible dust
10:11which is aluminium in this form you would normally recognize it as sandpaper
10:18or Emery paper it’s a very hard material and that’s why we don’t want that
10:27material on our slide ways okay so that’s some of the interesting
10:31properties of this material the other thing I’d like to point out to you is
10:35the weird errors and shapes that have occurred on these two G’s here now this
10:43one was done with a live download from the PC and I’ve noticed this before that
10:52once we start getting slightly complicated files and this isn’t a very
10:55complicated file but once we get in quite large files what tends to happen
11:00is it seems as though the processor can’t handle input information output
11:06information at the same time and it loses its datum position as you can see
11:11it’s drifting all over the place and even when I downloaded the file and held
11:19it on the computer it was still doing this the only time I had success with
11:27cutting and with engraving was when I loaded the file onto a memory stick and
11:33transferred the file into the machine via a memory stick now this problem is
11:38not unique to this machine I’ve seen on my China blue machine as well
11:43well where do we go from here we’ve got a machine that’s full of abrasive dust
11:50and a fantastic material one of the things I would like to try while we’re
12:02working with this material is something that we haven’t yet tackled and that is
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
12:083d engraving that’s exactly what it sounds like we’re not going to cut to
12:15just a single depth as we did when we were doing this engraving we’re going to
12:20have variable depth across each one of our scans so I think first of all we’ll
12:27go away and take a look at the file that I’m going to be using for dealing with
12:32this 3d engraving and then we’ll come back here and we’ll try and cut it by
12:38which time hopefully I’ll have top it up my fill tank again now this is an
12:45especially prepared bitmap it’s not just an ordinary photograph it’s not
12:49something you can produce yourself if we look at it carefully it’s got a very
12:53strange sort of waxy look to it if we look at the top here we’ll see that
12:58there’s white and these little berries look they look white and part of the
13:02Eagle here is white well in the background we’ve got black zero is black
13:10and white is 255 that’s 256 colors in total 254 of them are shades of black
13:20and white mix ie gray now the machine is actually capable of subdividing its
13:29power output into 256 levels as well so that as it scans across here while it’s
13:38doing a scan it can decide that this is full power this is less power and when
13:44we get to white it’s probably almost no power and then it goes back to dark
13:49black which is full power again so as the beam moves across one sweep it’s
13:56continuously changing power so eventually wish you’ll finish
13:59up carving this shape because it’s not something that happens instantly after
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
14:04just one pass you have to do multiple passes to get the relief into this
14:09picture let’s look up here at the bitmap handle and we can see here that the
14:16resolution of this picture is 200 pixels per inch when we look at the size of the
14:23picture up here it’s 61 millimeters wide about two and a half inches and then two and a
14:31half inches that means that at 200 pixels per inch there’s about 500 pixels
14:37across that picture and every one of those pixels is mapped when we create a
14:44file and the computer is deciding what the power level should be at every step
14:49across so it’s quite a phenomenal piece of software engineering to be honest so
14:55we don’t have to do anything with this bitmap handle at the moment we could if
14:59we wanted change the we do it gently we can change the shade on the picture we
15:08can play with that a little bit now the shades of gray on here are mapped onto
15:12here off of a 3d object so that they’re basically like the contour lines on a
15:18survey map equal shades of gray are all at the same level the depth in the
15:25picture and that’s how we get the 3d ness into it you do not get 3d if you
15:31just take an ordinary photograph and try and do 3d with it so how do we get the
15:383d effect so now we’ll bring up the layer
15:42parameters and this is where we’ve got to look very carefully at what we’re
15:45doing it is output yes speed per minute well if you go too fast the computer
15:53just can’t keep up with the speed that we’re going and you tend to lose
15:59resolution in your picture so I found that something like about 100
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
16:04millimeters a second is a good speed to work with is it blowing well certainly
16:10in this instance yes depending on the material
16:14we may make a different decision processing mode is scanned yes and the
16:20this is where we’re going to use something that we haven’t talked about
16:24before which is max min power now the lowest power that the tube will fire at
16:33is around about 8% so I’m going to set that to I think 9% and that well choose
16:47a number but the output curve is nonlinear and ideally what we’d like to
16:52do is make sure that we keep a linear relationship between all the colors in
16:56here so mmm always a compromise decision here I
17:00think I’ll probably start off at something like about 50% power and what
17:07that means is that white will represent 9% and black will represent 50% power
17:14and between those two numbers we’ve got two hundred and fifty four steps of
17:19power now the really important thing that you must do is to put that tick in
17:26there, output direct otherwise these two numbers will have no effect at all X
17:32swing yes so we’ve chosen a resolution of 200 dots per inch so what I’m going
17:39to do is to do a very quick calculation to work out what the interval is and
17:44that calculation is basically 25.4 which is one inch in millimeters and we’re
17:52going to divide that by 200 which is the resolution and the answer to that is
17:580.127 and that’s what we’re going to put in this here 0.127 so we’ve got
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
18:07200 pixels across and 200 steps down per inch bear in mind I mentioned earlier
18:14that we had problems with transferring the file to the machine what I’m going
18:19to do now is to save the file as a u file so then we’ll go out to them
18:24and load it into the machine now bear in mind I was telling you how this didn’t
18:29want to load properly well I’m doing the same with this particular file I’m
18:33making sure that I load it via a memory stick and you can see how big the file
18:39is because it’s taking absolutely ages to load well I think it’s probably going
18:44to be about three or four minutes by the time it’s loaded I’m placing two of my
18:49very strong Neodymium magnets on each corner so I’ve got eight magnets on
18:56here pushed hard up against the corners because I’m anticipating that because of
19:03the dust that’s going to be produced and the fact that I’m going to have to do
19:07multiple cuts I’m going to have to clean this in between the cuts and I do not
19:13want this to move okay now I’ve got the machine lid closed but I have got an air
19:18gap underneath to let all the to let plenty of air flow through there but of
19:23course this is producing a dust which probably doesn’t get carried very far in
19:30the air stream it gets blown away by the air assist and that’s because it’s quite
19:37a heavy dust if you listen you can actually hear the
19:42beam changing its power
19:52now I’m afraid this is not exactly a rapid process we’re probably going to
19:57have to go over this maybe four five times
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
20:03because this is actually still quite a hard material the softer the material
20:07the faster it cuts well this is why I wanted to put the magnets on there
20:12because we’re going to have to clean all the dust off this job carefully
20:18before we go for the next cut because this dust is not very absorbent and it
20:25will prevent the next layer from cutting I’ve also increased the power this time
20:30so we get a bigger difference between our deep and our shallow cuts you can
20:35probably just see here where it hasn’t actually cut and that’s because that’s
20:40where it was white the darker parts are cutting adjust a little bit deeper what
20:45we’ll have them cutting proportionately a lot deeper this time now I’ve moved
20:49the head out of the way but of course as soon as I press the start button it will
20:54go back to the original origin point that it was set to and it will work from
20:59there so the fact that I’ve moved the head out of the way has not caused me a
21:02problem so here we go start
21:08and there you can see we’ve got a much more violent cut
21:16and I would say we’re probably cutting on black maybe half to three-quarters of
21:23a mil deep
21:27now I have to say that I would not do this on my other China blue machine
21:32because I don’t have a proper air filtration system on there on this
21:36machine we’ve got the Purex filter which has got what four levels of filter
21:43I’ve got a crude filter inside the machine here and then there’s a
21:46pre-filter a HEPA filter and an active carbon filter built into the Purex unit
21:51and then it recirculates the air I can hardly smell anything but if I lift this
21:56lid there is a bit of a strange smell now I don’t know exactly although I’ve
22:00done some research I don’t know exactly what the gaseous products are when we
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
22:06are breaking down this aluminium hydroxide silica dust of any sort can
22:13cause respiratory problems so that’s another reason why I’m keeping this lid
22:18closed okay well I’ll move the head out of the
22:21way again
22:26and we can already see that we’re beginning to get some nice shape into it
22:30I could use an airline but I don’t want to blow this abrasive dust everywhere I
22:36can even put the power a little bit more to 70% and if I want a deeper cut still
22:42I can’t increase the power anymore but what I can do is decrease the speed well
22:48this is going into our fourth cut now and I think you can see that we’re
22:53starting to get some pretty good relief
23:00Hey look at this we’re really getting some good definition
23:05into it now look reckon we might need one or maybe two more passes and then we
23:10should be there what we might do is one more pass like that well here we are
23:14after five cuts now and hey look at this
23:22this is superb this material is a wonderful material for 3D engraving
23:30but I don’t think we can handle the dust problem so this may be my one and only
23:38attempt at 3d engraving with Corian on any machine I think we should probably
23:46put a fine cut on there now and we’ll call that it so let’s change the cut to
23:53we’ll leave it at 8% and we will change the maximum down to maybe 30%
24:03well just while this is making its final cut
Transcript for Laser Cutting and Laser Engraving Corian (Cont…)
24:07I’ve got some more rocket fuel and I’ve got a solid fuel booster as well
24:13there we go we will go and wash it under a tap and see whether we can
24:20maybe get a little bit more colour back into it because it’s probably covered in
24:23dust at the moment
24:42well thank you very much for your attention and we shall see you in the
24:46next session where we might talk a little bit more about Max and min
24:51cheerio for now
